Line 2,754: | Line 2,754: | ||
</div> | </div> | ||
</div> | </div> | ||
− | <p> | + | <p>Double transformation with pgRNA and new pdCas9</p></div> |
− | <div class="collapsible-body"><span> | + | <div class="collapsible-body"><span> |
+ | |||
+ | <b>Goal:</b> | ||
+ | |||
+ | 1. Transformation of pgRNA and pdCas9 into DH5a and TG1-cells. | ||
+ | |||
+ | |||
+ | |||
+ | <b>Procedure:</b> | ||
+ | |||
+ | <p> | ||
+ | Both pdCas9(2) and pgRNA(2) with anti-luxS were simultaneously transformed into competent cells (DH5α) after the following protocol:</p> | ||
+ | |||
+ | <ul> | ||
+ | <li>Thaw competent cells on ice.</li> | ||
+ | <li>Add pdCas9(2) (5μL) and pgRNA(2) with anti-luxS (5μL) to the same tube containing competent cells.</li> | ||
+ | <li>Incubate the cells on ice for 20min.</li> | ||
+ | <li>Heat shock the cells for 45s at 42℃.</li> | ||
+ | <li>Incubate the cells on ice for 2min.</li> | ||
+ | <li>Add LB- medium (900μL).</li> | ||
+ | <li>Incubate the cells for 1.5h (max. 2h) at 37℃ with shaker.</li> | ||
+ | <li>Plate the cells (100μL) on agar with AMP and CM </li> | ||
+ | <li>Centrifuge the cell culture for 3min at 6800g.</li> | ||
+ | <li>Discard the supernatant (200μL)</li> | ||
+ | <li>Resuspend the pellet with the remining supernatant in the tube</li> | ||
+ | <li>Plate the cells (100μL) on agar with AMP and CM.</li> | ||
+ | </ul> | ||
+ | |||
+ | <b>Results: </b> | ||
+ | |||
+ | Colonies on the plates with DH5a. No colonies on the plates with TG1. </span></div> | ||
</li> | </li> | ||
<li> | <li> |
Revision as of 18:35, 13 October 2018
In our lab journal we have thoroughly documented what we have done in the laboratory, what our goals each session has been, how we have worked and results from each session. If you want a closer look on our methods/receipies, take a look at our protocol.
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Week25
Week 25
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Jun20
Our first day in the laboratory!
Goal: Incubate the Escherichia coli (E. coli) samples which carry pgRNA and pdCas9 on agar plates separately with antibiotics.
1. LA- medium (1.5%) was made.
2. Two different agar plates were made – one containing ampicillin (AMP) and one containing chloramphenicol (CM).
Incubation of bacteria
Two Escherichia coli (E. coli) samples which carry pgRNA and pdCas9 plasmids respectively, were ordered from Addgene. E.coli carrying the pgRNA plasmid were plated on agar plates with AMP, while E.coli carrying the pdCas9 plasmid were plated on agar plates with CM. Incubation for 24 h at 37℃.
Results:
There was growth and single colonies on all the plates. -
Jun21
Inoculation of E.coli
Goal: Inoculate a colony from each agar plate in LB- medium with antibiotics.
Procedure
One colony of pgRNA- and pdCas9- bacteria were picked and inoculated in LB-media (25 mL) with 25 µL of the associated antibiotic (AMP or CM). The cell cultures were incubated at 37℃ in a shaking incubator at 204 rpm.
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Jun22
Isolation and verification of pgRNA and pdCas9
Goal: Isolate and verify that the E.coli carry pgRNA and pdCas9.
Plasmid isolation
pgRNA and pdCas9 were isolated from the incubated bacteria prepared yesterday (June 21) by following the miniprep protocol.
Determine plasmid concentration and purity
The concentration of plasmids and the purity of each sample were determined by using Nanodrop.
Restriction digest and plasmid verification
The presence of pgRNA and pdCas9 in the cell cultures were verified after following the restriction digest protocol and separation of the DNA fragments by gel electrophoresis.
Week26Week 26
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Jun25
Transformation of pgRNA and pdCas9 into competent cells
Goal: Transform pgRNA and pdCas9 into competent cells (E.coli K-12 DH5α).
Procedure:
The extracted pgRNA and pdCas9 plasmid DNA were transformed into E.coli K-12 DH5α cells.
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Jun26
Transfer successful transformed cells to LB-medium and preparation of standard curves for the InterLab study
Goal:
Inoculate successful transformed competent cells to LB-medium, and prepare the standard curves for InterLab study.
Procedure:
Inoculate colony from agar plates to LB-medium:
A colony from each agar plate was selected and inoculated to LB- medium with antibiotics. Competent cells with pgRNA were transferred to LB- medium with AMP, while competent cells with pdCas9 were inoculated into LB- medium with CM. The cell cultures were incubated at 37℃ with shaker.
Preparation of 1xPBS solution for the InterLab-study.
Preparation of agar plates with CM, LA- and LB-medium.
Preparation of standard curves for InterLab study:
Calibration 1: OD 600 reference point – LUDOX protocol
A conversion factor to transform absorbance data from plate reader into OD600 was obtained in spectrometer by measuring four replicates of LUDOX CL-X and ddH2O. The data were imported into Excel sheet.
Calibration 2: Particle standard curve – Microsphere protocol
The solution of silica beads provided in the kit from iGEM HQ, was vortexed before dilution with water (96 μL Silica beads in 904 μL dd H2O). A serial dilution of microspheres was obtained by adding 100 μL dd H2O into 4x11 wells (E2, F2, G2, H2…E12, F12, G12, H12) on a 96 well plate. Microsphere stock solution (200 μL) was pipetted into E1 and 100 μL of the solution was transferred to E2 and mixed well before transferring 100 μL to E3. The procedure repeated until 100 μL solution was pipetted into E11, and 100 μL was transferred to liquid waste. The dilution series was repeated for row F, G and H. The absorbance of the samples was measured by a plate reader with shaker at 24℃. The data were exported to Excel sheet.
Results:
Sett inn bilde her. -
Jun27
Isolation of pgRNA and pdCas9 from compentent cells (DH5α) and preparation of stock solution for calibration 3 for InterLab study
Goal:
Isolate plasmids from competent cells (DH5α), and prepare the fluorecein stock solution for InterLab study.
Procedure:
Dilution of cell cultures:
Each cell cultures (successful transformed competent cells from day 5 – 26.06.2018) (2.5 mL) were transferred into fresh LB-medium (22.5 mL) with CM (22.5 μL). The new cultures were incubated for about 2 hours at 37℃ with shaking .
Measurement of the cell density:
The cell density of the new cultures was measured at OD 600, after calibration with water (blank sample).
Plasmid isolation and determination of concentration:
The plasmids were isolated from the competent cell after the protocol of ZR plasmid miniprep kit (see lab journal from day 3 - 22. June. 2018).
The concentration of the plasmids was determined by using Nanodrop.
Restriction digest:
The plasmids from each culture (5 μL) were digested by mixing with 10xbuffer (2 μL), distilled water (12.5 μL) and restriction enzyme BspHI (0.5 μL). The solution was centrifuged down before the samples were incubated over night at 37℃.
Results: -
Jun28
Plasmid verification and storing the cell cultures
Goal:
Verify that the successfully transformed DH5α cells carry pgRNA or pdCas9, and store the cell cultures for future use.
Procedure:
Plasmid verification:
The digested plasmid samples from yesterday’s incubation (lab 6 – 27. June.2018) were separated by gel electrophoresis.
Bacteria glycerol stocks:
The cell cultures made from 27. June were stored in a glycerol stock (500 µL cell culture and 500 µL 50% glycerol) in the freezer at -80℃.
Results:
Plasmid verification:
L, pR1, pR2, pC1 and pC2 are the DNA-fragments from ladder solution, the two samples of pgRNA and pdCas9, respectively. From Figure 1 the two fragments with 1.5 kb and 1.0 kb were found from the fragments of pgRNA after digestion by BspHI. The fragment with 100 bp from the digested pgRNA is not visible on the gel, probably due to masking of the dye colour at the bottom of the gel. Two bands from the digested pdCas9 with 2.7 kb and 4 kb were also detected. By comparing the results og gel elecrophoresis obtained from today's experiment with the results from day 3 (22. June. 2018), one can clearly see that the bands with the expected length from successful transformed competent cells, are much clearer. Hence, this also indicate the samples from the successful transformed DH5α cells are purer, which is also true by comparing the results from Nanodrop (see day 6 - 27. June. 2018, and day 3 - 22. June. 2018). -
Jun29
Insertion of anti-luxS via PCR and fluorescence standard curve for InterLab study
Goal:
Insert anti-luxS in pgRNA plasmid, and generate fluorescence standard curve for the InterLab study.
Procedure:
Insertion of anti-luxS gene and amplification of pgRNA with PCR.
InterLab – Calibration 3
A fluorescence standard curve was generated from the data obtained after measuring the fluorescence of the serial dilution of fluorescein.
The fluorescence was measured with the following settings:
Temperature: 24℃
Gain (manual): 56
Wave length [nm] Band width [nm] Excitation 494 4 Emission 525 20
Results:
InterLab – Calibration 3:
Figure 1 shows the florescence standard curve in the concentration interval [0, 2.5 μM], with a R2 value of 0,9956. The model of the fluorescence standard curve is:
Week27Week 27
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Jul2
Separation, isolation and transformation of linear DNA (pgRNA with anti-luxS)
Goal:
- Separate the PCR product from circular DNA
- Isolate the linear DNA (pgRNA with anti-luxS from the gel
- Transform the linear DNA into competent cells
- InterLab study - transformation of plasmids to competent cells
Procedure:
Separation of linear DNA from circular DNA:
The leaner DNA obtained from PCR (from day 8 – 29. June. 2018), was separated from the circular DNA (original plasmids) after running the sample (25 μL) mixed with loading dye (5 μl) on gel electrophoresis (gelGreen) simultaneously with a ladder (1 μL gene ruler + 1 μL loading dye + 4 μL dH2O) for 50 min at 90 V. The sample and the ladder were prepared by the gel electrophoresis protocol.
Gel digestion and DNA isolation:
The agarose was digested and the DNA was isolated from the sample following the gel purification protocol.
Determine the DNA concentration and purity:
The concentration and the purity of the isolated DNA was determined by using Nanodrop.
Transformation of PCR product to competent cells: The PCR product (5 μL) was transformed to competent cells after following the transformation protocol.
InterLab – transformation of plasmids to competent cells:
The plasmids listed on the protocol, was transformed into competent cells (DH5α) after the following protocol:
- Thaw the competent cells on ice (10 min), and pre-chill the eppendorf tubes.
- Resuspend the DNA in the wells (provided by iGEM HQ) with dH2O (10 μL).
- Add competent cells (50 μL) to the eppendorf tubes.
- Add resuspended DNA (1 μL) to the Eppendorf tubes.
- Incubate on ice for 25 min
- Heat shock the cells for 45 s at 42℃ in water bath
- Incubate on ice for 5 min.
- Add LB-medium (950μL) to the tubes
- Incubate for 1h at 37℃ with shacker
- Pipette each sample (100 μL) to agar plate with CM
- Centrifuge the samples for 3 min at 6800g, discard supernatant (800 μL) and resuspend the pellet with the remaining supernatant
- Pipette each sample (100 μL) to agar plate with CM
- Incubate overnight at 37℃.
Results:
Separation of linear DNA from circular DNA:
Figure 1 shows the image of the gel where the linearized DNA was separated from the circular DNA. The linearized DNA is approximately 2 kb. The linearized DNA fragment was then cut out from the gel and stored in eppendorf tube.
Note! Due to UV-light exposure, the DNA may mutate. In this case, this may affect the later steps of our project. The worse scenario, mutation of anti-luxS. Hence our CSRPRi system may not recognize luxS in the bacteria. Biofilm production will not be inhibited…
Determine the DNA concentration and purity:
Table 1 shows the results of the linear pgRNA (2) from PCR (probably with anti-luxS gene).
Table 1: The concentration and the relative purity of the pgRNA (2) from PCR.Concentration [ng/μL] 260 nm/280 nm 260 nm/230 nm 52.8 1.90 0.27
From the 260/230 ratio, the sample has a relatively a small amount of nucleic acids. Probably, it is contaminated by the agarose from the gel electrophoresis. On the other hand, the 260/280 ratio is ok, indicating that the sample contains a relatively larger amount of RNA than DNA. InterLab – transformation of plasmids to competent cells:
No visible colonies were detected on agar plates, except the positive and negative control cells. -
Jul3
Inoculation of successful transformed competent cells and InterLab study
Goal:
- Inoculate colonies of successful transformed competent cells
- InterLab study - transformation of plasmids to competent cells
Procedure:
InterLab – transformation of plasmids to competent cells:
No visible cell colonies were formed on the agar plates that were incubated on day 9 - 02. Junly. 2018. Only the positive and negative control cells formed colonies.
Therefore, the remaining plasmids (6 μL) were transformed to the competent cells and plated on agar based on the same protocol from day 2. Jul. 2018. During the incubation at 37℃ with shaker, the incubation time was extended to 2 h. The cell cultures were centrifuged, and 700 μL supernatant was discarded, and the pellets were resuspended with the remaining supernatant. The cell cultures were then plated on agar plated with CM, and incubated overnight at 37℃.
Inoculation of successful transformed competent cells:
Colonies of successful transformed competent cells with pgRNA (probably containing anti-luxS) were inoculated from the agar plates (from day 9 – 02. July. 2018) to LB-medium with AMP. The cell cultures were incubated with shaker overnight at 37℃.
Results: -
Jul4
Verification of successful inserted anti-luxS in pgRNA
Goal:
- InterLab - transformation of plasmids into competent cells
- Verification of succsesful insertion of anti-luxS in pgRNA(2)
Procedure:
InterLab – Transformation of plasmids to competent cells
There has been a mistake of numbering the plates with plasmids provided by iGEM HQ. Therefore, we did not get any cell colonies from the previous two transformations…
The plasmids (1.5 μL) from the right wells were transformed to competent cells by following the transformation protocol from day – 02. July. 2018, after resuspension of the plasmids in the wells.
Cell density:
The cell cultures with pgRNA(2) (probably with anti-luxS), inoculated from day 10 – 04. July. 2018, were diluted 10 times by following the same dilution procedure from day 6 – 27. June. 2018. The cells were incubated with shaker for 1h before measuring at OD 600.
Plasmid isolation:
The plasmids from the two cell cultures were isolated after the same mini-prep protocol from day 3 – 22. June. 2018. The concentration and the purity of the isolated plasmids were measured by Nanodrop.
Restriction digest and gel elecrophoresis:
Insertion of anti-luxS gene was verified after the protocol of restriction digest and gel electrophoresis (see the protocols from day 3 – 22. June. 2018). The restriction enzyme PstI was chosen, and the expected length of the plasmid fragments are 490 bp and 2094 bp.
Note! PstI has a cut site at the anti-luxS gene in the plasmid.
Bacteria glycerol stock:
Two samples of the diluted cell cultures (made at this morning), were stored in 50% glycerol solution at -80℃ (the same green box with the other successful transformed cells with pgRNA (without anti-luxS) or cells with pdCas9 plasmids).
Results:
InterLab - Transformation:
Colonies were formed on agar plates with CM.
Cell density:
Table 1: Absorbance of the cell cultures with pgRNA(2) after 1 h incubation at 37℃ with shaker.Culture OD 600 pR2 (1) 0.954 pR2 (2) 0.998 Concentration (ng/μL) 260 nm/280 nm 260 nm/230 nm pR2(1) 37.2 2.06 4.29 pR2(2) 123.3 1.77 1.01 -
Jul5
Double transformation and InterLab study - Inoculation
Goal:
- Transform both pdCas9 and pgRNA with anti-luxS into competent cells
- InterLab study - inoculate colonies in LB-medium
Procedure:
Double transformation of pdCas9 and pgRNA with anti-luxS:
Both pdCas9(2) and pgRNA(2) with anti-luxS (isolated from day 11 – 05. July. 2018) were simultaneously transformed into competent cells (DH5α). The amount of added pdCas9(2) (5 μL) and pgRNA(2) with anti-luxS was 5 µL per/plasmid, and it was added to the same tube containing competent cells. The cells were plated on agar with both AMP and CM. A couple of steps were added at the end, and the purpose was to increase the cell concentration plated on agar, and probably increase the possibility of colony formation. The cell culture was therefore centrifuged for 3 minutes at 6800g, and the supernatant discarded. The pellet was then resuspended and cells were plated.
InterLab – Inoculation of colonies
A colony from each agar plate was inoculated in LB-medium (5 mL) with CM (5 μL). The cell cultures were incubated overnight at 37℃ with shaker.
Results:
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Jul6
Inoculation of successful double transformed cells, interLab study - Cell measurement
Goal:
- Inoculate successful double transformed cells (probably carrying pdCas9 and pgRNA with anti-luxS)
- InterLab study - measure absorbance and the fluorescence of each cell cultures
Procedure:
Inoculation of successful double transformed cells
- A colony from each agar plates with AMP and CM (made from day 13 – 05. July 2018) was picked and inoculated in LB medium (20 mL) with AMP (25 μL) and CM (25 μL).
- The cell cultures were incubated at 37℃ with shaker.
InterLab – Cell measurement
We were not able to measure the cell cultures today, since the TECAN device was under reparation.
Each cell cultures were stored with 50% glycerol (see day 7 – 28. June. 2018) at -80℃.
Results:
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Jul7
Verification of pdCas9 and pgRNA with anti-luxS after double tranformation
Goal:
Verify that both pdCas9 and pgRNA with anti-luxS are tranformed into DH5α cells
Procedure:
Dilution of cell culture:
Each cell cultures, inoculated and incubated from day 13 – 07. July. 2018, were diluted (1mL) with LB medium with antibiotics until the OD 600 reached 1.9.
Plasmid verification:
Plasmid isolation:
The plasmids were isolated from each cell cultures after following the mini-prep plasmid protocol from day 3 – 22. June. 2018. The concentration and the purity of the samples were determined by Nanodrop.
Restriction digest and gel electrophoresis:
The plasmids in each sample were digested with restriction enzymes BamHI-HF and PstI with the following ingredients and amounts:
- 7.1 μL Plasmids
- 0.5 μL PstI
- 0.5 μL BamHI-HF
- 2 μL NEBuffer 1.1
- 10.4 μL ddH2O
Note! NEBbuffer 1.1 was chosen instead of Cut smart since the activity of PstI in Cut smart was 50%.
The activity of the enzymes in NEBbuffer 1.1:
BamHI-HF: 100%
PstI:75%
After the plasmids have been degraded by restriction enzymes, the fragments were separated by gel electrophoresis.
Results:
Plasmid verification:
Plasmid isolation:
Sample Concentration [ng/μL] 260 nm/280 nm 260 nm/230 nm 1 219.9 2.01 1.82 2 35.3 2.03 3.86
The bands on the gel, corresponded with the expected fragments (6705bp, 2094bp, 465bp, 25bp) from digestion of the plasmids by PstI and BamHI-HF. Therefore, we concluded that both of pdCas9 and pgRNA with anti-luxS have successfully been transformed into DH5α cells.
Week28Week 28
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Jul9
No lab
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Jul10
No lab
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Jul11
No lab
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Jul12
InterLab Study: Revive bacteria glycerol stock
Goal : InterLab Study: Revive bacteria glycerol stock
Procedure: The frozen bacteria glycerol stock made from 6th of July were thawed on ice. Each culture were inoculated in LB medium with CM (5 mL), and incubated over night at 37°C. -
Jul13
InterLab Study: CFU/mL/OD calculations
Goal:
Count colony forming units on plates spread the day before.
Procedure:
Counted CFU on all 36 plates incubated 13. July.
Results:
The colonies on agar plates, from yesterday’s incubation, were counted and registered:CFU Dilution 3 Dilution 4 Dilution 5 1.1 195 6 1 1.2 185 2 0 1.3 203 15 3 2.1 222 19 2 2.2 38 22 1 2.4? 52 15 1 3.1 113 56 3 3.2 112 12 2 3.3 127 25 2 4.1 79 4 0 4.2 75 10 1 4.3 107 3 1 -
Jul14
InterLab – CFU/mL/OD calculation
Goal:
Counting colonies on each agar plate, and calculate CFU/mL in starting samples with an OD600 = 0.1.
Procedure:
The colonies on the agar plates, prepared from yesterday’s incubation, were counted and registered.
Results:
Table 1: The average values of counted colonies from two cultures of positive and negative controls with different final dilution factor (dilution 1 = 8x104, dilution 2 = 8x105, dilution 3 = 8x106).Positive control Negative control Culture 1, dilution 1 194.3 117.3 Culture 1, dilution 2 7.7 31.0 Culture 1, dilution 3 1.3 2.3 Culture 2, dilution 1 104.0 87.0 Culture 2, dilution 2 18.7 5.7 Culture 2, dilution 3 1.3 0.7
Week29Week 29
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Jul16
Transformation of the RFP-biobrick (test)
Goal:
Transform the RFP-biobrick (BBa_J04450) into competent DH5α-cells.
Procedure :
Before doing the transformation the biobrick was resuspended with 10 µL dH2O in the plate (position 23O, plate 7). The cells with and without the biobrick (negative control) were both incubated and plated after the transformation. The negative control was plated on LA-petri dishes while the transformed cells was plated on LA-petri dishes with CM.
Results:
There was only one colony on each plate -
Jul17
Colony picking biobrick (test) and transformation
Goal :
1. Get colonies of the transformed DH5α (biobrick) 2. Get colonies on the negative control plate
Procedure:
1. Due to the lack of colonies on the negative control plates, new plates was streaked.
2. New LA-plates without antibiotics were made.
3. Colonypicking the two colonies from the plates with the transformed bacteria in to liquid medium.
4. The transformation of bacteria with the biobrick plasmid was redone on four plates because of the lack of growth on the plates (see 16.07.18).
Results:
There were more colonies on the four new plates, and they were light red as well (About 20 colonies). The new negative control plates had colonies as well.
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Jul18
RFP biobrick fluorescens measurement (test)
Goal:
1. To get a descriptive curve for the rise in fluorescens (transformed DH5α)
2. Find out how often the measurements need to be done.
Procedure:
The second batch of plates from transformation and the negative control:
1. Colonypicking and exchange to liquid medium
Measurements of the first batch (Tecan):
1. Measured the OD of the blank (LB and CM), and measured the OD of the two cultures.
2. For the next measurements we diluted the cultures by 1:100 in separate tubes.
3. Incubation of the tubes
4. The first measurement was done in the Tecan, and repeated for every 30 minutes and then 1 hour (because of minor changes in values)
5. The measurements was set overnight as well using the following script: FluorescenceLong. The data was set to 588 nm absorbance, 584 nm excitation, 607 nm emission, 37°C, 40 gain, 150 kinetic cycles, 300s shaking (orbital 3 mm amplitude).
Results:
The second batch from transformation has turned red. From the measurements of the test batch we have an idea of the increase in fluorescence intensity and the change in absorbance over time. This can be used to determine the timing of the second batch with the negative control as well.
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Jul19
Biobrick: Preparations, Fluoresence microscopy
Goal:
Prepare for measurements tomorrow.
Learn about fluorescence microscopy
Procedure:
Preparations:
Made LA-petri dishes with CM. Diluted cultures of the biobrick Bba_J04450 and negative control and incubated them at 37°C overnight.
Demonstration and training in fluorescence microscopy:
Astrid Bjørkøy showed us how to use the fluorescence microscope, and we tried it out by taking photos of cultures of the Bba_J04450 biobrick. She also told us how to count cells by adjusting a photo's threshold and calculate based on image size.
Results:
The biobrick Bba_J004450 was very bright. We used excitation 561 nm and emission ca 625-680 nm as the biobrick was too bright at emission 607 nm. Consider using another laser further away from excitation point (584 nm) for the real photos of the biobrick, and the improved biobrick.
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Jul20
Biobrick: Red Fluorescent Protein measurement (FAILED)
Goal:
Measure the expression of the Bba_J04450 biobrick in transformed dH5α cells. This is done by measuring fluorescence.
Procedure:
1. Incubated dH5α, J04450 transformed cells were dilluted 1:100 with LB
2. 200 µL, 5 replicates of LB, LB with Chloramphenicol and 5 dH5α dillutions made from different batches were applied to a 96 well plate
3. Tecan plate reader was used to measure absorbance at 588 nm and fluorescence at excitation 584 nm and emission 607 nm with the following parameters:
- Temperature: 37,0°C, varying from 36,5°C to 37,5°C
- Kinetic cycles: 750
- Gain: 40
- Z position: 18055 µM
- Shaking: 300 s
- Orbital shaking amplitude: 3 mm
Results:
The wells dried out, presumably due to us choosing not to use a lid on the plate, and the measurements were therefore aborted by the machine.
Week30Week 30
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Jul23
Make super competent cells of the TG1
Goal:
Make supercompetent cells of the E.coli - TG1 strain
Procedure:
DAY 1:
- Made Psi media, transformation buffer 1 and transformation buffer 2.
- Made an E.coli TG1 culture in a small flask with 10 mL Psi- medium. Inoculated culture at the end of the day and left the flask for incubating while shaking and at 37°C overnight.
Results:
-
Jul24
Make supercompetent cells of the TG1, day 2
DAY 2:
This was done from an overnight culture of TG1-cells, see protocol. Results:
There was no growth on the plates with CM and AMP after the transformation (25. July. 2018), so the conclusion was that the cells were not supercompetent. The protocol was then updated and optimized for another trial. -
Jul25
Miniprep and transformation of TG1-cells
Goal:
1. Transformation of TG1-cells with DNA that includes pdCas9 and pgRNA with antiluxS-gene.
2. Make LA-plates with both CM and AMP antibiotics
Procedure:
pgRNA with antiluxS and pdCas9 has already been transformed into E.coli DH5α. The plasmids were isolated and extracted by the miniprep protocol. Transformation of the TG1-cells with the extracted plasmids was done, and the bacteria were incubated.
Results: No bacterial growth has been observed. -
Jul26
Preparations for biofilm measurements
Goal:
1. Make media for the biofilm measurements (LB and M63B1)
2. Prepare TG1, TG2 buffers and Psi medium for supercompetent cells.
Procedure:
1. Made three versions of the two media with pH-values at 4.5, 7.2 and 9.5. The media was then autoclaved and sugar will be added before use of the media.
2. Made TG1, TG2 buffers and Psi medium.
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Jul27
Make supercompetent cells of TG1, second attempt
Goal:
1. Make supercompetent cells of TG1 by following an improved protocol.
Week31Week 31
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Jul30
Transformation of TG1-cells and flow cytometry test
Goal:
1. Transformation of TG1-cells with DNA that includes pdCas9 and pgRNA with antiluxS-gene. 2. Learn and conduct a flow cytometry test of the E.Coli DH5a that contains the Bba_J04450-biobrick and a negative control. The goal was also to optimize a protocol for the biobrick measurements.
Procedure:
pgRNA with antiluxS and pdCas9 has already been transformed into E.coli DH5α. The plasmids were isolated and extracted by the miniprep protocol, and the cells transformed and incubated. For the transformation, 5 µL of the miniprepped plasmids were used instead of 2 µL.
2.
Results: Noticeable bacterial growth was observed on all plates, with no apparent contamination. -
Jul31
TG1 colonypicking
Goal:
1. Make cultures out of plates made on the 30th of July, prepare for test digest.
2. Make DH5α cultures for later use in biobrick measurements.
Procedure:
Colonypicking into five beakers with 25 mL LB, 25uL Amp and 25 µL CM. Incubation at 37°C, 225 RPM overnight. New LB-media was made. -
Aug1
Miniprep, Nanodrop, Test digest
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Aug2
Verification of transformation of TG1 and preparation of media for biofilm measurements
Goal:
1. Confirm successful transformation of TG1 with pgRNA and PdCas9 with anti-luxS.
2. Prepare media for biofilm measurements
3. Inoculate TG1 in newly made media
Procedure:
Verification of the plasmids was done by miniprep, nanodrop, test digest and gel electrophoresis. Different amounts of glucose was added to the respective media.
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Aug3
Measure OD + change medium
Goal:
Week32Week 32
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Aug6
E.Coli TG1 biofilm measurement
The two E.Coli TG1 96-well plates made yesterday (06.08.2018) underwent the Crystal Violet Assay protocol (see Protocols), and the biofilm produced was measured by measuring absorbance at 590 nm with Tecan Infinite 200 Pro plate reader. -
Aug7
Incubate DH5α and TG1 in chosen media for biofilm measurements.
Goal:
- Incubate DH5α and TG1 (with pgRNA and pdCas) in selected media (LB and M63B1, pH 7.2, 0.4%/0.8% Glucose) - Make Tetracycline stock solution (5.0 mg/ml)
Procedure:
Incubated the frozen DH5α-stocks in LB (with CM and AMP) for a few hours. Inoculated into the chosen media in eppendorf tubes. Incubated TG1 into the chosen media in eppendorf tubes overnight. Made 5mg/mL Tetracyclin-solution (inducer). Note: light sensitive.
Protocol:
- Tetracyclin-HCl(powder): 54 mg
- Ethanol: 7 mL
- dH2O: 3 mL
After being incubated for some time tetracyclin solution was added to the eppendorf tubes do induce the transcription of Cas9, and the culture tubes were further incubated. -
Aug8
Incubation of cell cultures for biofilm assay and preparation of M63B1 medium
Goal :
1. Incubate cell cultures on 96-well plates for biofilm assay
2. Make M63B1 medium
Procedure :
Preparation for biofilm assay:
1. Overnight cultures (with TET) was diluted until OD600 = 0.1
2. Each diluted culture (100μL) was added on 96-well plate and incubated for 4 h at 37℃
3. After 4 h incubation, the non-adhered cells were removed by washing the wells with physiological saline and the supernatant was discarded.
4. New medium (100 μL) was added to each well and the plate was incubated for 24 h at 37℃.
Note! The media that were added to the wells right before 24 h incubation did not contain TET
M63B1 medium:
M63B1 medium was made after following the protocol from 26. July. 2018
Results: -
Aug9
Preparation of media with TET, and incubation of cell cultures on 96-well plate for biofilm assay
Goal :
1. Preparation of media with tetracycline (2 μM)
2. Incubate cell cultures with and without tetracycline (TET) on a 96-well plate for the 24 h biofilm assay.
3. Measure the absorbance of CV- assay with and without TET, made from yesterdays’ incubation.
4. Prepare TG1 and dH5α cell cultures in growth medium (LB or M631B) with or without TET (2 μM).
Procedure :
Preparation of media with TET (2 μM):
1. Tetracycline (TET) (50 μL, 0.5 mg/mL) was added to a 25mL LB medium with 0.4% glucose, AMP and CM. The same amount of tetracycline was added to LB medium with 0.8% glucose, AMP and CM
2. For the final M63B1 medium (0.5 L) with MgSO4*7H2O, AMP and CM and 0.4% or 0.8% glucose, TET (1mL, 0.5 mg/mL) was added.
Preparation of 96-wells plate for 24h biofilm assay:
1. Overnight cultures were diluted with or without TET (2 μM) containing media (LB or M63B1) until a target OD600 = 0.1.
2. Each diluted culture (100 μL) were incubated on a 96-wells plate for 20 h at 37℃.
Absorbance measurement of CV-assay:
1. The supernatant was discarded from a 24h incubation of cell cultures on a 96-wells plate (prepared from 08. August. 2018) and rinsed with PS (100μL).
2. The biofilm was fixed by adding methanol (100 μL, 99%) and waited for 15min. The supernatant was discarded, and the plate was airdried.
3. CV-solution (100 μL, 0.1%) was added to each well and coloured the biofilm for 20 min. The excess CV was washed away with dH2O 4. Acetic acid (150 μL, 33%) was added to the each well.
5. The absorbance was measured at Abs 590 nm
Results: -
Aug10
Preparation of overnight cultures for biofilm assay, and storage of TG1 cells with pgRNA and pdCas9
Goal :
1. Prepare overnight cultures in LB (0.4% or 0.8% glucose, with AMP and CM) or M63B1 (0.4% or 0.8% glucose, with AMP and CM) with or without TET.
2. Wash the 96-well plate (after 20 h adhesion - prepared from 09.08.2018) with physiological saline, add new media and incubate the plate.
3. Make bacteria glycerol stocks of TG1 cells with pgRNA and pdCas9.
Procedure :
Preparation of overnight culture:
TG1 and dH5α were incubated in eppendorf tubes with different media (LB or M63B1 with glucose (0.4% or 0.8%), AMP and CM) with or without TET (2 μM) for overnight at 37℃ with shaking.
Preparation for biofilm assay:
1. After 20 h adhesion (plate prepared from 09. August. 2018), the non-adhered cells were removed by washing the wells with physiological saline (PS) and the supernatant was discarded.
2. New medium (100 μL) was added to each well and the plate was incubated for 24 h at 37℃.
Bacteria glycerol stock preparation:
TG1 cells with pgRNA and pdCas9 (500 μL) was stored with glycerol (500 μL, 50%) at -80℃.
Results : -
Aug11
Preparation of overnight cultures for biofilm assay
Goal :
Prepare 96-well for cell adhesion and CV-assay
Procedure :
The OD of some of the overnight cultures was not optimal for continuing the procedure of CV assay. New cell cultures were made.
96-well plates for 24 h, 48 h and 72 h incubation were made. However, since the cell cultures could not be diluted to OD = 0.1, the results of the CV assay will not be comparable. -
Aug12
Incubation of cell cultures for biofilm assay
Goal :
Preparation for cell adhesion on 96-well plates for 24 h, 48 h and 72 h incubation.
Procedure :
1. The overnight cultures were resuspended, before dilution until a target OD = 0.1.
2. The diluted cell cultures were resuspended and added on 96-well plates and incubated for 4 h at 37℃.
3. After 4 h incubation, the wells were washed with physiological saline (100 μL) and the supernatant was discarded.
4. New media (100 μL) were added to the plates, and the plates were incubated at 37℃.
Results :
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Aug13
Biofilm measurements after 24hrs
Procedure:
Followed the crystal violet assay:
Changed medium in the plate for 48 and 72 hrs.
Results:
Results did not show any clear trend. Excel sheet attached.
Wells with only medium, not cells, showed too high absorbance measurements, probably because of contamination of the mediums. Decided to autoclave all the mediums again. Will take measurements at 48 hrs, but not at 72 hrs. -
Aug14
Biofilm measurement after 48 hrs
Goal:
- Measure biofilm after 48 hrs.
- Prepare RRVT-Biobrick and biobrick backbone
- Ligate and transform RRvT- biobrick and biobrick backbone into DH5alpha cells.
1. Performed the Crystal Violet Assay procedure for the plate designated for 48hrs and for the plate that initially was designated for 72 hrs measurement. -
Aug15
Biobrick ligation and transformation
Goal:
- Ligate plasmid backbone and RRvT-plasmid and transform into cells.
- Due to the lack of colonies from yesterdays transformation the ligation of plasmid backbone and RRvT-plasmid and transformation into E.Coli Dh5α cells was redone.
- Preparations of plasmid backbone and RRvT-biobrick:
Made enzyme master mix for plasmid backbone by adding 5μL NEB buffer 2, 0.5 μL EcoRI-HF, 0.5 μL PstI, 0.5 μL BSA and 18.5 μL dH2O to an Eppendorf tube.
Made enzyme master mix for RRvT-biobrick by adding 5μL NEB buffer 2, 0.5μL EcoRI-HF, 0.5 μL PstI and 19 μL dH2O to an Eppendorf tube. Incubated mix for 20 min at 50℃.
Digested Plasmid backbone by adding 4 μL linearized backbone (25 ng/μL for 100 ng) and 4 μL of enzyme master mix for plasmid backbone.
Digested RRvT-biobrick by adding 4 μL of the biobrick and 4 μL of the enzyme master mix for RRvT-biobrick. Digested both reactions at 37℃ for 90 min and did heat kill at 80℃ for 20 min.
- Ligation:
Added 2 μL of digested plasmid backbone.
Added 2 μL of digested RRvT-biobrick.
Added 1 μL T4 DNA ligase buffer.
Added 0.5 μL of T4 DNA ligase.
Added water to 10 μL.
Ligated at 16℃ for30min. Did heat kill at 80℃ for 20 min.
Transformed E.Coli Dh5α cells with 1-2 μL of product following the protocol for transformation.
Inoculated .. plates and let them incubate at 37℃ to the next day.
Aug16Preparation for biobrick (RRvT) measurement and biofilm assay
Goal:
- Inoculate successful transformed cells into LB medium with CM.
- Revive TG1 and DH5α cells in LB medium with AMP, CM and 0% glucose.
Preparation for biobrick (RRvT) measurement:
Successful transformed cell colonies from yesterday's incubation were inoculated into LB - medium with CM and incubated at 37°C with shaking.
Preparation for cell cultures for biofilm assay:
TG1 and DH5α cells with pgRNA and pdCas9 were revived in LB medium with AMP, CM and 0% glucose. The cell cultures were incubated at 37°C with shaking.
Aug17Preparation for biofilm assay
Goal:
- Dilute the overnight cultures for biofilm assay.
- Do Crystal Violet assay after 3 h, 5 h and 8 h of incubation of a 96-well plate.
Procedure:The media for biofilm assay were made by adding the following ingredients:
- LB 0.4% glucose, TET: 10 mL LB, 10µL AMP, 10µL CM, 0.2 mL 20% Glucose, 19.7µL 0.5mg/mL TET
- LB 0.8% glucose, TET: 10 mL LB, 10µL AMP, 10µL CM, 0.4 mL 20% Glucose, 20µL 0.5mg/mL TET
- LB 0.4% glucose: 10 mL LB, 10µL AMP, 10µL CM, 0.2 mL 20% Glucose
- LB 0.8% glucose: 10 mL LB, 10µL AMP, 10µL CM, 0.4 mL 20% Glucose
- M63B1 0.4% glucose, TET: 10 mL M63B1, 10µL AMP, 10µL CM, 10 µL 1M MgSO4*7H2O, 0.2 mL 20% Glucose, 19.7 µL TET
- M63B1 0.8% glucose, TET: 10 mL M63B1, 10µL AMP, 10µL CM, 10 µL 1M MgSO4*7H2O, 0.4 mL 20% Glucose, 20 µL TET
- M63B1 0.4% glucose: 10 mL M63B1, 10µL AMP, 10µL CM, 10 µL 1M MgSO4*7H2O, 0.2 mL 20% Glucose
- M63B1 0.8% glucose: 10 mL M63B1, 10µL AMP, 10µL CM, 10 µL 1M MgSO4*7H2O, 0.4 mL 20% Glucose
Biofilm assay:
- Pipette 3-4 mL overnight cultures to sterile tubes (total 16 tubes).
- Centrifuge the cultures for 10 min at 2000 rpm at 9°C.
- Remove the supernatant.
- Add 3-4 mL media (LB/ M63B1, with 0.4%/ 0.8% glucose, with/ without TET) to 2 tubes each.
- Resuspend/ vortex the cultures, and measure OD 600.
- Dilute the cultures until target OD 600 = 0.1 and store the cells on ice until they are added to the wells.
- Resuspend/ vortex the cultures, add 100 µL culture to each well on the plate.
- Seal the top of the plate with parafilm, and incubate the plate at 37°C.
- Do CV assay after 3 h, 5 h, 8 h, 24 h and 48 h incubation.
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Aug20
Preparation for 3h, 5h, 8h, 24h, 30h CV and Bactiter-Glo Assay.
Goal:Redo CV assay from 17th August to check the validity of previous results.
Perform Bactiter-Glo Assay parallell to CV Assay (3h, 5h, 8h, 24h, 30h) to examine the amount of living cells in biofilm.
Procedure:Crystal Violet Assay: Same procedure as from 17.08.2018.
Bactiter-Glo Assay
Results:The results and measurement settings can be found in the attached files.
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Sept5
Introduction of site directed mutagenesis on pdCas9 and make medium for V. natrigens
Goal:Make LB medium and 10x v2 salts for Vibrio natrigens
Amplify and introduce site directed mutagenesis in pdCas9
Procedure:LB - medium
10x v2 salts:
Make the salt solutions after the following recipe:- 11.935 g NaCl (204 mM)
- 0.3134 g KCl (4.2 mM)
- 4.710 g MgCl2*6H2O (23.14 mM)
- 1 L ddH2O
Site directed mutagenesis:
Forward and reverse primers for site directed mutagenesis were designed and ordered from Sigma Aldrich. Introduce site directed mutagenesis in pgCas9 via PCR after following the protocol from 29. June. 2018. The first PCR was not successful. The primer annealing temperature was changed, and the elongation time as well. -
Sept6
Introduce site directed mutagenesis in pdCas9 and amplify RRvT and pSB1C3e
Goal: Introduce site directed mutagenesis in pdCas9 Amplify RRvT and pSB1C3 via PCR
Procedure: Site directed mutagenesis in dCas9: pdCas9 was amplified via gradient PCR, where the annealing temperatures were 57.3 ℃, 59.3 ℃, 61.1 ℃ and 64.1℃ with an elongation time for 5 min. The samples were stored in the fridge after the PCR was finished. Amplification of RRvT and pSB1C3: RRvT and pSB1C3 fragments were amplified by running the samples (6 µL FW primer, 6 µL REV primer, 1 µL template, 12.5 µL Takara Hi-Fi PCR premix) on PCR with the following settings: annealing temperature 37 ℃ for 10 s, elongation temperature 72 ℃ for 1 min. The samples were stored in the fridge after the PCR was finished.
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Sept7
Gel purification of PCR products (pdCas9, RRvT and pSB1C3), incubate V. natriegens
Goal:Separate the PCR products of RRvT and pSB1C3 on gel, and miniprep the desired fragments on the gel. Incubate Vibrio natreigens (V. natriegens). Do another round of site directed mutagenesis on pdCas9 via PCR.
Procedure: Gel purification of RRvT and pSB1C3 on gel:5 μL loading dye was added to the PCR products (25.5 μL). The PCR products were separated on Gel green (90 V, 40 min). The desired fragments were cut out from the gel and collected in eppendorf tubes Gel digestion and DNA isolation of RRvT and fragment of pSB1C3: The PCR products with the desired length on the gel was isolated by following after the same protocol from 02.07.2018.
Inoculation and incubation of V. natriegens:Sample of V. natriegens sent by the iGEM team from Marburg, was inoculated and incubated by following after the protocol provided by the team.
Introduce site directed mutagenesis in pdCas9:PCR mix with pdCas9 was prepared after following the same protocol from 29.06.2018. Two samples were set on two different programs: 3 step PCR: DNA denaturation temperature at 98℃, primer annealing temperature at 55 ℃ for 10 s, elongation temperature at 72 ℃ for 7 min. 2 step PCR: same conditions as 3 step PCR without the primer annealing step.
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Sept10
Gibson assembly of RRvT and backbon and transformation of SDM pdCas9 and assembled RRvT into competent cells
Goal:
Gel purification of PCR products Gel digestion and isolation of desired DNA fragments Assemble RRvT and pSB1C3 via Gibson assembly Transform pdCas9 and the assembled RRvT into competent cells
Procedure:Gel purification: The PCR products were separated on gel green RRvT: 25.5 µL DNA, 5.05 µL loading dye pdCas9: 25 µL DNA, 5 µL loading dye
Gel digestion and DNA isolation:
The desired fragments (RRvT: approx. 2000 bp, pdCas9: approx. 6000 – 7000 bp) were cut out from the gel. The gel was digested by following after the protocol from 02.07.18.
Transformation of SDM pdCas9 into competent cells:
6 µL DNA was transformed into competent cells by following after the protocol from 25.06.18.
Gibson assembly of RRvT and pSB1C3:
The fragments were assembled together by following the protocol provided from the kit 2 µL RRvT, 8 µL pSB1C3 (0.03 – 0.2 pmol fragments), 10 µL assembly master mix was incubated in a thermocycler at 50C for 15 min. The sample was stored on ice for transformation.
Transformation of assembled RRvT and pSB1C3 into competent cells:
2 µL Gibson assembly product was transformed into competent cells by following after the protocol from 25.06.2018.
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Sept11
Double transformation with pgRNA and new pdCas9
Goal: 1. Transformation of pgRNA and pdCas9 into DH5a and TG1-cells. Procedure:Both pdCas9(2) and pgRNA(2) with anti-luxS were simultaneously transformed into competent cells (DH5α) after the following protocol:
- Thaw competent cells on ice.
- Add pdCas9(2) (5μL) and pgRNA(2) with anti-luxS (5μL) to the same tube containing competent cells.
- Incubate the cells on ice for 20min.
- Heat shock the cells for 45s at 42℃.
- Incubate the cells on ice for 2min.
- Add LB- medium (900μL).
- Incubate the cells for 1.5h (max. 2h) at 37℃ with shaker.
- Plate the cells (100μL) on agar with AMP and CM
- Centrifuge the cell culture for 3min at 6800g.
- Discard the supernatant (200μL)
- Resuspend the pellet with the remining supernatant in the tube
- Plate the cells (100μL) on agar with AMP and CM.
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